January, 1979

Volume 044Article 22

I D A H ODEPARTMENT OF FISH & GAME

Joseph C..Greenley, Director

Project IPC-26

EVALUATION OF TRANSPLANTING SNAKE RIVER

STEELHEAD TROUT TO THE PAHSIMEROI RIVER, 1978

Period Covered: 1 July 1977 to 30 June 1978

by

Melvin ReingoldPrincipal Fishery Research Biologist

i

TABLE OF CONTENTS

Page

ABSTRACT ................................................ 1

INTRODUCTION ............................................ 2

OPERATIONS AND RESEARCH - 1978 .......................... 2Delivery of Fish ................................... 2

Homing Research .................................... 2Adult Steelhead Spawn-taking Procedures_ ........... 3Adult Hauling ..................................... 5

Adult Radio Tracking ............................... 5

MARKED ADULT RETURNS .................................... 9Hatchery Feeding - Smolt Behavior Experiment ....... 9NMFS Transport Evaluation .........................12

ADULT RETURNS ..........................................131974 Release - 1973 Brood Year (Clearwater Race) .. 131975 Release - 1974 Brood Year ....................141976 Release - 1975 Brood Year ....................14

DORSAL FIN DEFORMITY RECOGNITION, ....................... 14

STEELHEAD ANGLER CHECK STATIONS ........................ 14

ACKNOWLEDGEMENTS ....................................... 17

LITERATURE CITED ....................................... 17

LIST OF TABLES

Table 1. Numbers of adult steelhead released in variouslocations in the Salmon River drainage,distances transported and returns to thePahsimeroi weir ............................... 7

Table 2. Numbers of marked adult steelhead countedat the Pahsimeroi weir and in the upperSalmon River sport catch, fall 1977-spring1978 ......................................... 11

Table 3. Summary of color coded wire tag recoveriesfrom adult steelhead that returned to thePahsimeroi station in 1978 ................... 13

Table 4. Releases, returns, marks used, etc. of theNiagara Springs-Pahsimeroi River steelheadprogram, 1973-1978 ........................... 15

LIST OF TABLES (Continued)

PageTable 5. Summary of data collected at the steelhead

angler check station operated near NorthFork, Idaho, October-November, 1977 ............ 16

Table 6. Summary of data collected at the steelheadangler check station operated near NorthFork, Idaho, February-March, 1978 .............. 16

LIST OF FIGURES

Figure 1. Over 1,800 adult steelhead excess to theneeds of the Niagara-Pahsimeroi projectwere transported and released in theupper Salmon River drainage ..................... 6

mi)....... 8

na

Figure 2. Radio tracking adult steelhead was limitedto a distance of approximately .4 km (1/4from the fish .. . . ' ...................

Figure 3. A vehicle with an externally mounted anten

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allowed us to search and track from the roadalong the Salmon River .......................... 8

Figure 4. Steelhead released in the East Fork of theSalmon River were observed actively construct-ing redds and spawning in the vicinity ofthe release area ............................... 10

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EVALUATION OF TRANSPLANTING SNAKE RIVERSTEELHEAD TROUT TO THE PAHSIMEROI RIVER, 1978

ABSTRACT

Returning marked adult steelhead from 1976 feed experiments showeddouble the returns from smolts fed an Oregon Moist Pellet diet over thosereared on dry feed.

Grading steelhead smolts to favor fast growing "leaders" in 1976 led toincreased adult returns in 1978.

Adult steelhead excess to program needs were transported and releasedin various locations in the Salmon River drainage. Many of these fish spawnedsuccessfully, close to the area of liberation, with some penetration intoadjacent tributary streams.

Spawn-taking procedures at the Pahsimeroi station were modified in 1978with the goal of improving the hatchery product and increasing the smolt toadult return ratio.

The steelhead sport fishery in the Salmon River for the 1977-78 fishrun was one of the most intense and successful in many years. Check stationdata indicated that anglers fishing the Salmon River above the South Forkharvested an estimated 60% of the hatchery run (4,200 fish).

Author:

Melvin ReingoldPrincipal Fishery Research Biologist

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INTRODUCTION

The Niagara Springs Steelhead Hatchery and Pahsimeroi SteelheadCollection Facility operations are part of Idaho Power Company's ob-ligation to relocate steelhead and salmon stocks from the Snake Riverto the Salmon River because of inundation and blockage of their ancestralmigration routes and spawning beds by Hells Canyon Dam.

This project was initiated in 1966, with the release of the firststeelhead smolts from fish trapped at the base of Hells Canyon Dam. Pre-sent project operations include obtaining steelhead eggs from adults re-turning to the Pahsimeroi station from prior smolt releases, incubatingthe eggs to the advanced eyed stage and shipping them to Niagara SpringsHatchery near Wendell, Idaho, for hatching.

The steelhead fry are placed in raceways at Niagara Spring Hatcheryand reared until the following spring when they are trucked back to thePahsimeroi River and released as seaward-bound smolts.

OPERATIONS AND RESEARCH - 1978

Delivery of Fish

Approximately 1,266,000 steelhead juveniles were transported and re-leased in the Pahsimeroi River from Niagara Springs Hatchery in 30 truck-loads between 20 March and 26 April 1978. ,All fish were released directlyinto the river near the adult steelhead weir site. In addition, 34,200smolts were transported from Dworshak National Fish Hatchery and releasedin the Pahsimeroi at the weir site on 18 April 1978.

Of the 1,266,000 Niagara Springs-reared smolts delivered in 1978,1,22.0,800 were 1977 brood year Pahsimeroi River-stock from eggs taken fromthe adult steelhead that returned to the weir in the spring of 1977. Thebalance of the release consisted of 24,300 fish that were 1977 brood yearDworshak-origin steelhead hatched and reared at Niagara Springs from eggs,and 20,900 that were 1977 Dworshak-origin fish delivered as fry to NiagaraSprings Hatchery in October, 1977. The Dworshak-origin steelhead were partof a research experiment to investigate the effects of hatchery imprintingon homing ability.

Homing Research

In the spring of 1977, a small number of adult steelhead that enteredthe facilities at Dworshak National Fish Hatchery on the Clearwater Rivercarried fin clips that indicated possible Niagara Springs-Pahsimeroi origin.The 1974 smolt release from Niagara-Pahsimeroi were reared from Dworshakfingerlings delivered in October 1973, and speculation arose concerning earlyimprinting and its effects on homing behavior.

To investigate that phenomena, four groups of coded wire tagged smoltswere released in the Pahsimeroi River in April 1978. One group consisted ofsmolts hatched and reared at Niagara Springs Hatchery from eggs taken at DworshakNFH in the spring of 1977. A second group of smolts were reared from steelhead

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fry hatched and raised to 343/kg (156/lb) at Dworshak NFH and delivered toNiagara Springs in October 1977. A third group of smolts were Pahsimeroi-origin Niagara-reared steelhead to serve as experimental controls. A fourthgroup of smolts hatched and reared at Dworshak NFH were transported from thathatchery and released directly in the Pahsimeroi River in April 1978.

These releases will compare adult returns to the Pahsimeroi from:

1. Niagara-reared Dworshak-origin smolts from eggs.

2. Niagara-reared Dworshak-origin smolts from 4-month rearedDworshak fry.

3. Niagara-reared Pahsimeroi-origin smolts (control).

4. Dworshak-reared Dworshak-origin smolts.

The three groups of fish reared at Niagara Springs (egg origin, fryorigin, and controls) were marked with a coded wire tag in October 1977. Tagswere applied to approximately 40,000 fish from each group.

In the winter of 1977-78, a severe disease outbreak at Niagara Springscaused high mortality among all fish on the station. The loss among theexperimental groups that had been handled and stressed during the coded wiretagging operation was higher than the untagged fish on the station and ranas high as 39%. Growth of the tagged fish was retarded compared to unhandledfish and upon delivery to the Pahsimeroi tn April, all three groups averagedapproximately 32/kg (14.5/lb) and 150 mm (5.9 in) total length. These threeNiagara-reared groups, while directly comparable with each other, were not aslarge or healthy as the normal annual product from Niagara Springs Hatchery.A large portion of these fish were below the 170 mm (6.7 in) minimum lengthnecessary for good emigration and adult returns may be low. Symptoms ofFurunculosis and Red-throat diseases were present in the smolts at release.

The smolts delivered to the Pahsimeroi directly from Dworshak NFH were ingood health and averaged 19/kg (8.5/lb) and 177 mm (7.0 in) total length.

The difference in the size and health between the Dworshak and Pahsimeroismolts must be considered when evaluating adult returns in 1980, 1981, and 1982.

Adult Steelhead Spawn-taking Procedures

Past work on the Pahsimeroi program has repeatedly shown that a minimumsized smolt of 170 mm (6.7 in) appears to be necessary to ensure good down-stream emigration and adult returns. In order to culture the annual smolt pro-duction at Niagara Springs Hatchery to meet that goal to the maximum levelpossible, two factors emerge above all others: the elimination of excess numbersof fry over that needed for production, and an advancement and compression ofthe time range over which eggs are delivered to the hatchery.

Delivering more eyed eggs to the hatchery than is needed to meet the pro-duction quota leads to overcrowding of fish, increased incidence of disease,greater size variation, lower growth rates, increased workload, elevated feedcosts and, eventually, higher total fish loss and a poorer quality smolt.

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The past policy of taking the eggs from all female steelhead entering thePahsimeroi trap often resulted in "overloading" the Niagara Springs Hatcherysystem and at times hindered the potential of that station for approachingthe 170 mm (6.7 in) total length minimum for its final product.

Past egg taking-rearing procedure at the Pahsimeroi-Niagara Springsfacilities has also included rearing juveniles from all segments of thereturning adult run; from the earliest to the last fish to arrive. Thisusually led to a time spread of nearly 2 months between the first and lastfry hatches at the station. Two months rearing time can make a significantdifference in final size at Niagara Springs Hatchery and can mean the differencebetween a smolt or non-smolting fish. The wide time span between first and lastegg takes also creates space and grading problems, contributes to cannibalism,and increases work loads.

The popular argument for taking eggs from all portions of a fish run is toattempt to maintain genetic diversity and prevent the possible loss or severereduction of the early and late arriving or ripening segments of the population.This reasoning is based on two premises: one; if the fish were ever to be re-introduced to their primary environment they may not be as suited as theyoriginally were, and two; if downstream factors eliminated a segment of therun as it passed through the Columbia or Snake River, then there would be othersegments to survive. I do not consider either of these factors to be an over-riding consideration. The first premise is no longer a possibility and neitherthe downriver passage conditions or the degree of genetic selection at thePahsimeroi is so severe as to cause a threat from the second.

Commencing in the spring of 1978, a modified spawntaking procedure wasinitiated at the Pahsimeroi facilities which I believe will result in increasedsmolt quality and adult returns to that station. Basically, this consisted ofdelivering eggs to Niagara Springs Hatchery from the forward main body of the runonly. The first few small egg takes from the small number of early ripeningadults were not delivered to Niagara Springs. When the main body of the runripened up, the Niagara Springs needs (2 million eggs) were delivered to thehatchery. When the quota was fulfilled the remaining adults were transported tovarious locations on the upper Salmon River and tributaries and released to spawnnaturally.

In 1978, this resulted in all eggs delivered to the Niagara Springs incu-bators within a 16-day period.. The incubation-hatching-starting phase wasconsiderably compressed over prior years and the result was a more uniform andlarger product at the time of this report (January 1979).

Obviously the program will vary with the size of the annual adult return.Some years of low runs will require that all eggs from all female be taken andthe time range will be correspondingly wide. Years of high returns, such as1978, may result in all eggs delivered within a 2-week period.

I believe this program will result in increased numbers of adult steelheadreturning to the Pahsimeroi River for less cost in materials, supplies and laborat the hatchery. Some increased cost for transporting adults out of thePahsimeroi facilities to upriver locations will be necessary but will result inenhancing the upper Salmon River steelhead sport fishery and will seed presently

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under utilized anadromous fish habitat with naturally rearing juvenilesteelhead.

Adult Hauling

After all eggs were taken to satisfy program needs, 1,833 excess adultsteelhead were transported by tank truck to various locations in the SalmonRiver drainage (Fig. 1). To monitor the amount of return to the Pahsimeroiweir and prevent double-counting of adults, the transported fish were givenan identifying mark by making holes in thee opercle w1th a paper punch. A l ladults entering the Pahsimeroi trap were inspected for marks and the presenceof any opercle punches were noted. The first time a marked steelhead reenteredthe Pahsimeroi trap it was given an additional mark and the fish again trans-ported upstream.

Out of 1,568 adult steelhead transported to locations upstream from thePahsimeroi River, 26 (1.6%) were recaptured at the trap. Of these 26 fish,22 (85%) were males. Only one fish returned a second time. In general, thefish transported further distances returned in fewer numbers than those re-leased closer to the Pahsimeroi.

Those steelhead released in both the Pahsimeroi River (205) and LemhiRiver (60) were released upstream of a weir and could not return back down-stream out of those rivers (Table 1).

Adult Radio Tracking

Because relatively large numbers of adult steelhead were being transportedto upstream areas in the spring of 1978, we felt the need to learn whetherthese fish would spawn successfully in a wild situation and to attemt todelineate the degree of straying after release prior to spawning.

On 6 April 1978, we installed miniature radio transmitters in four femaleadult steelhead taken from the holding pens at the Pahsimeroi trap. The fourfish were transported up the Salmon liver` about 96 km (60 mi) and released inthe main river at Robinson Bar bridge. Two hours after release all four radiosignals could be heard on a portable receiver mounted in a vehicle. Effectiverange was approximately .4 km (1/4 mi) (Fig. 2 3), Periodic tracking runswere conducted to monitor the movements of the four fish. Ne signal was detectedlonger than 9 days after the release date.

Steelhead number 1 (frequency 3.33) did not move from the Robinson Bar hole,where it was released, for 4 days (6-9 April). Tracking searches after that datefailed to locate that fish again.

Steelhead number 2 (frequency 6.43) was located 4:2 rm (2.6 mi) downstreamthe second day after release, 10.2 km (6.4 mi) downstream from the release pointon the fourth day after release and then was never located again.

Steelhead number 3 (frequency 7.22) remained at. the release site for 2 daysafter release, was found .3 km (.2 mi) upstream on day four, and .3 km (.2 mi)downstream on day seven. On the ninth day after release (14 April), the trans-mitter signal indicated the fish was in the same location as on the seventh day.There was no further contact after that date.

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Table 1. Numbers of adult steelhead released in various locations in the Salmon Riverdrainages, distances transported and returns to the Pahsimeroi weir.

Release area

Approximatedistance

from Pahsimeroi R.No. of fish

released

Punches on Sex, No. & No. of timesleft or returned to Pahsimeroi R.

right opercle* 1 2

East Fork 64 km 750 1R, or 2R M-2Salmon River (40 mi) F-1

Mid Salmon River 96 km 200 lL M-5(Robinson Bar) (60 mi) F-1

Valley Creek 120 km 200 1R, 1L M-10 M-1(75 mi) F-0

Upper Salmon R. 136 km 418 2L M-5(Decker Flat) (85 mi) 1L, 2R F-2

Lemhi River 56 km 60 None Released above Lemhi weir(35 mi) Zero recaptures.

Pahsimeroi

downstream

released from 205 Nonetrap upstream

26 1Total 1,833

7

8

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Steelhead number 4 (frequency 9.20) was located 1.3 km (,8 mi) upstreamon the second day, back at the point of release on the fourth day and 1 km(.6 mi) downstream on the seventh day. The area where fish number 4 was lo-cated on the seventh day is known locally as "Indian Riffle" and is one of thebest anadromous fish spawning areas in that section of the river, commonlyused by both steelhead and salmon. Although a visual sighting could not bemade, the area that the signal was emanating from was a likely area for reddbuilding and spawning. Another tracking run 2 days later failed to locatethat fish again, and no further contacts were made although periodic searchescontinued for over 80 km (50 mi) on either side of this last contact until 26April, 14 days later.

Field checks showed fish on newly constructed redds and actively spawningin the immediate release areas on the East Fork of the Salmon River within afew days after liberation (Fig. 4). Adult steelhead were seen spawning inLyon Creek and Slate Creek, small Salmon River tributaries in close proximityto the Robinson Bar release area. Wild steelhead spawners had not been seen inthese streams for many years and it appears these were transported Pahsimeroifish.

National Marine Fisheries Service (NMFS) personnel operating downstreammigrant collection facilities at Lower Granite dam reported seeing severalspawned out adult steelhead with opercle punch marks. No accurate recordswere kept on numbers or marks however (personal communication, Larry Basham,NMFS).

It appears that the steelhead transported to other areas from thePahsimeroi River spawned successfully under natural conditions, and limitedevidence suggests spawning occurred in close proximity to the area of liberationand some penetration of adjacent tributary streams occurred.

MARKED ADULT RETURNS

Hatchery Feeding - Smolt Behavior Experiment

In March 1976, we released four marked groups of 1975 brood year, NiagaraSprings-reared, Pahsimeroi-origin steelhead smolts as part of a feed-smolt be-havior research experiment.

Groups number 1, 2 and 3 were all hatched from the same egg take. Groupnumber 4 were fish hatched from the earliest egg takes and were intensely gradedduring the rearing process to produce the largest smolt possible.

Groups 1, 2 and 3 are directly comparable. Groups 1 and 2 average 198and 199 mm (7.8 in) total length at release and group 3 averaged 215 mm (8.5 in).All three groups averaged well above the 170 mm (6.7 in) minimum size neededfor good emigration. I do not consider the 16-17 mm (0.6-0.7 in) size differencebetween groups 1 and 2 and group 3 significant enough to account for thedifference in return numbers between these three groups. However, to correctfor the percent of the population less than 170 mm (6.7 in) total length Irecalculated the length frequency of groups 1, 2 and 3, eliminating those fishless than 170 mm. The modified length frequencies are as follows:

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Group #1 Group #2 Group #3

Range: 170-279 mm 170-289 mm 170289 mmAverage 212 mm 212 mm 220 mm% of release: 80% 83% 92%Total released: 24,500 25,300 25,200Corr. rel. no.: 19,600 21,000 23,200

The corrected release number is the actual number of smolts over 170 mmreleased into the Pahsimeroi River. Assuming that fish less than 170 mm didnot contribute to adult returns in any significant amount, this then makes thesmolt-adult return percentage directly comparable between groups 1, 2 and 3as so:

Group #1 Group #2 Group #3

Corr. rel. no.: 19,600 21,000 23,200Adult ret.: 29 28 67Return %: .15 .13 .29

Group #1, the control group, was started and reared for the entirehatchery cycle on dry feed. Group #2 was started on Oregon Moist Pellets(OMP) feed and reared on OMP until they were approximately 51/kg (23/lb) inOctober of 1975, and then switched to a dry diet for the remainder of therearing phase. Group #3 was reared entirely on OMP from start to finish.Group #4 was reared entirely on dry feed. Downstream migration monitoring inthe spring of 1976 showed group #3 migrating 2 weeks earlier than the othergroups. I attributed this behavior to final diet (Reingold 1977).

The 1-ocean returns from these four groups arrived back at the Pahsimeroiweir in the spring of 1978 and were checked in the upper Salmon River sportcatch in the fall of 1977 and spring of 1978 (Table 2).

Table 2. Numbers of marked adult steelhead counted at thePahsimeroi weir and in the upper Salmon Riversport catch, fall 1977 - spring 1978.

Group #1*RVAd(dry)

Group #2RV

(OMP/dry)

Group #3LVAd(OMP)

Group #4LV

(Large-dry) ,

Weir 29 28 67 218

Sport 6 15 9 34

Total 35 43 76 252

*This group of fish was utilized as an experimental control.

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The fish fed 100% OMP showed considerably larger returns (93-123%)than the other two groups. These fish displayed an earlier (stronger?)emigration behavior when released as smolts in 1976 (Reingold 1977). Ifwe relate this to a 1,000,000 fish smolt release it would mean 2,900 adultsback to the weir versus 1,500 or 1,300 for groups 1 and 2 respectively.

Group number 4, the "premium leaders" of the 1975 brood-year, returnedat a phenomenal rate of .87%. These fish were a true minimum size 170 mmsmolt. They ranged in size from 170 mm-319 mm (6.7-12.6 in total length andaveraged 238 mm (9.4 in). Their feeding regime is comparable to the controlgroup #1; both were reared on a 100% dry diet. These were the most vigorous,fastest growing fish on the station and I believe this is reflected in the.87% return percentage. They did not display the 2-week earlier emigrationbehavior as did the OMP fed group #3 (the second highest return). It isinteresting to speculate on what the return would have been on this group offish had they been reared on a 100% OMP diet.

The results of this experiment indicate that:

1. Feeding Niagara Springs steelhead smolts an OMP diet improved adultreturns. This may be related to final diet however, rather thantotal diet.

2. Past work indicating a minimum size of 170 mm as the lower limitfor steelhead smolts is further strengthened.

3. Grading steelhead smolts to favor fast growing "leaders" led toincreased adult returns.

The average size difference for 170 mm and longer fish between group 1and group 4 was 18 mm (0.7 in). I am inclined to favor vigor primarily, ratherthan this relatively small size differential for the difference in returnsbetween these two groups.

Experiments to further explore the effects of OMP as a final diet wereinitiated on the 1976 brood year - 1977 released smolts. Adults from theseexperiments are expected to return to the Pahsimeroi in the spring of 1979.

NMFS Transport Evaluation

One hundred and three adult steelhead that returned to the Pahsimeroiweir in the spring of 1978 carried color-coded wire tags in their snouts thatwere implanted by National Marine Fisheries Service personnel at Lower Graniteand Little Goose dams in the spring of 1975 and 1976. This was done to evaluatethe effects of transporting seaward bound smolts around the Snake and ColumbiaRiver dams versus allowing them to pass downstream through all the systems(controls).

The results from this program are shown in Table 3.

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Table 3. Summary of color-coded wire tag recoveries fromadult steelhead that returned to the Pahsimeroistation in 1978.

LowerGranite Dam

LowerGranite Dam

LittleGoose Dam

1975, 1976 1 9 7 6 Combinedreleases releases releases releases

Transports 4 40 39 83

Controls 0 11 9 20

Totals 51 48 103

NMFS data indicates approximately a 1.5:1 overall benefit for steelheadtransported in 1976 versus those not transported. This is a much lowerbenefit ratio than in past years. NMFS personnel. attribute this primarily toa change in the transport tanker release location due to construction work belowBonneville Dam (personal communication, Emil Slatick, NMFS).

ADULT RETURNS

1974 Release - 1973 Brood Year (Clearwater Race)

In the spring of 1976, I identified 395 adult steelhead that returned tothe Pahsimeroi station as 1-ocean adults from the spring 1974 release of Clear-water stock smolts. This was the first return of this stock of steelhead sub-stituted for the Pahsimeroi progeny lost as a result of an IPN epizootic atNiagara Springs Hatchery in 1973.

In the spring of 1977, I identified 74 adult steelhead that entered thePahsimeroi trap as 2-ocean Clearwater stock returns. These were considerablyfewer returns than expected as work done on the Clearwater River and at DworshakNational Fish Hatchery has shown that the majority of this race of steelhead(75-85%) return as 2-ocean adults there. The reasons for this lack of 2-oceanreturns are not apparent. A selective downriver net fishery could possibly con-tribute to it. Perhaps-hatchery rearing practices affect return behavior. Someresearch into this phenomenon could possibly be initiated.

In the spring of 1978, an estimated 29 additional steelhead adults from thisrelease returned as 3-ocean fish. The total return to the hatchery, excludingany contributions to the sport catch was 498 fish (.03%). This is the lowestsmolt to adult return ratio yet experienced at the Pahsimeroi station since theinitiation of the program.

These results, coupled with similar findings from other upper Salmon Riverresearch work indicate that the use of Clearwater River race steelhead for sub-stitution, replacement or enhancement of established Salmon River runs must beapproached with caution. Their suitability and adaptability may be within

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relatively tight constraints. Coded wire tagging experiments initiated in1978 will further explore this phenomenon.

1975 Release - 1974 Brood Year

In the spring of 1975, we released 1,331,000 Pahsimeroi-origin smolts,reared at Niagara Springs Hatchery, in the Pahsimeroi River. I estimatedthat 1,395 of these steelhead returned as 1-ocean adults in the spring of 1977.

In the spring of 1978 I classified an additional 533 2-ocean returnees asbeing from this smolt release. I do not expect any significant returns of 3-ocean fish from this release. This brings the total brood year return to theweir (not including sport harvest) to 1,928 fish (.14%).

1976 Release - 1975 Brood Year

In the spring of 1976, we released 1,610,000 Niagara-reared steelheadsmolts into the Pahsimeroi River. The 1-ocean adults from this release returnedto the Pahsimeroi in the spring of 1978. We classified 2,242 fish countedthrough the trapping facilities as adults from this brood year. Additional 2-ocean adults are expected to return in the spring of 1979 (Table 4).

Of the 2,803 adult steelhead counted into the facilities in 1978, 1,550were females (55.3%), and 1,253 (44.7%) were males.

DORSAL FIN DEFORMITY RECOGNITION

In the spring of 1978, I inspected 362 adult steelhead spawner carcassesto determine the degree of dorsal fin deformity. I classified the fins intothree categories:

Class I - Strongly deformed, easily recognizable.

Class II - Moderately deformed, recognizable with education.

Class III - Slight deformity or none, not recognizable. I

classified the 362 inspected fish as follows:

Class I - 323 (89%)

Class II 35 (10%)

Class III - 4 ( 1%)

Ninety-nine percent of the 1978 hatchery adult returnees were recognizableby deformed dorsal fins.

STEELHEAD ANGLER CHECK STATIONS

The steelhead sport fishery in the Salmon River for the fall 1977 spring 1978fish run was one of the most intense and successful in many years. Estimates drawnfrom check station data indicate that anglers in the Salmon River above the South

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16

Fork harvested an estimated 60% of the hatchery run, about 4,200 fish.

During the fall fishery we identified 65.5% of the 580 steelhead inspectedat the station as hatchery origin. During the spring fishery the ratio ofhatchery to wild fish was 80.7%.

Table 5. Summary of data collected at the steelhead anglercheck station operated near North Fork, Idaho,October-November 1977.

Steelhead Hours per PercentDates Anglers Hours Kept Released fish hatchery10/1-2 187 988 11 1 82.3 5510/8-9 150 802 19 1 40.1 4210/15-16 197 1,014 48 17 15.6 5610/22-23 239 1,392 77 15 15.1 7710/29-30 309 2,735 127 16 20.7 6611/5-6 329 2,749 164 33 13.9 6811/11-12 340 2,845 107 35 20.0 7011/19 98 506 27 0 70Totals 1,849 13,031 580 118 18.7 65.5

Table 6. Summary of data collected at the steelhead anglercheck station operated near North Fork, Idaho,February-March, 1978.

Steelhead Hours per PercentDate Anglers Hours Kept Released fish hatchery2/18-19 202 1,030 52 3 18.7 792/25 51 275 17 0 16.1 763/4-5 248 1,542 63 6 22.3 903/18 82 567 19 0 29.8 58Totals 583 3,414 151 9 21.3 80.7

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ACKNOWLEDGEMENTS

The research conducted on the Niagara Springs-Pahsimeroi project wouldnot be possible without the combined effort and interest of the personnelwho operate the facilities. Tom Levendofske and Albert Herrin of thePahsimeroi Collection Facility have my gratitude for their hard work anddedication to the projects initiated at that station.

Charles R. (Bob) Quidor, Jerry Mowery, Paul Smith and Dave May of theNiagara Springs Hatchery have made research experiments possible by theircooperation, dedicated labor and interest in the projects.

Fishery Research Biologist Steve Pettit provided valuable assistance onthe radio tracking work accomplished in 1978.

Idaho Power Company representatives, such as Director of EnvironmentalAffairs Wendell Smith, continue to make research possible on the Niagara-Pahsimeroi program by their support of the IPC financed projects.

LITERATURE CITED

Reingold, M. 1977. Evaluation of transplanting Snake River steelhead troutto the Pahsimeroi River, 1976. 1 July 1975 to 30 June 1976. IdahoDept. of Fish & Game Report.